Littelfuse FLSR 15 FLSR015 Fuse

The Littelfuse FLSR 15 (FLSR015) is a critical Class RK5 fuse engineered for heavy-duty industrial and HVACR applications. Operating as a 600V 15A time delay fuse, this dual-element component provides superior overcurrent protection for circuits with high inrush currents, such as motor branch circuits and transformer primaries. Its current-limiting design significantly restricts let-through energy, protecting downstream components from the destructive forces of short circuits. Built with a 13/16" x 5" industrial cartridge form factor, it fits standard Class R fuse blocks and includes a rejection feature to prevent the installation of lower-rated fuses.

With an interrupting rating of 200,000 Amps RMS symmetrical at 600VAC and 20,000 Amps at 300VDC, the FLSR015 is a versatile slow-blow fuse for service entrance switches and industrial control panels. The Littelfuse POWR-GARD series ensures consistent response times, minimizing nuisance tripping while maintaining a 10-second minimum delay at 500% of the rated current. This dual-element time-delay performance makes it the industry standard for general purpose circuit protection where reliability is non-negotiable.

• Enhanced Motor Protection: The dual-element design handles motor starting surges without unnecessary opening, extending the life of your HVACR equipment.
• High Interrupting Capacity: Safely clears faults up to 200kA, ensuring the safety of industrial control panels and switchboards.
• Current-Limiting Performance: Reduces magnetic and thermal stress on electrical components during short-circuit events for superior branch circuit protection.
• Standardized Compatibility: Replaces any standard 600V RK5 fuse, making it a drop-in solution for service entrance switches and feeders.

Can I use this fuse in a 250V system?
Yes, the 600VAC rating is the maximum allowable voltage. You can safely use this RK5 fuse in any system rated at 600V or less, including 480V and 240V circuits.

What is the difference between FLSR and FLNR fuses?
The FLSR-series is rated for 600V applications, while the FLNR-series is rated for 250V. Both are Class RK5 and offer time-delay characteristics, but the FLSR is necessary for higher-voltage industrial feeds.

Does this fuse fit in a standard Mersen or Bussmann holder?
Yes, the Littelfuse FLSR015 follows standard Class RK5 dimensions and is a direct cross-reference for the Bussmann FRS-R-15 and Mersen TRS15R.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.